In the conventional way for a body-fat measuring apparatus for measuring in-vivo impedance and computing body fat quantity, many measuring devices are proposed such as a device using a body-weight measuring device and hand/foot electrodes disclosed in Japanese Patent Publication No.5-49050 and Japanese Laid-Open Publication No.7-12635, a device using movable hand electrodes disclosed in Japanese Patent Publication No.7-51242, a device using a body-weight measuring device and foot electrodes with a body-height measuring device disclosed in Japanese Patent Laid-Open Publication No.7-100122.
When examinee's in-vivo impedance is measured by hand electrodes, it needs to keep examinee's arm region approximately at right angle to his/her torso region so as to obtain a measurement value stably, and also needs to keep the angle the same in each measurement especially for assuring the same measured quantity for every measurement. Accordingly, in the body-fat value measuring devices using hand electrodes, it is conventionally suggested to secure the hand electrode elements at a predetermined position, such as Japanese Laid-Open Publication No. 7-12635, or to keep examinee's arm region at right angle to his/her torso region himself/herself by examinee's visual adjustment, such as Japanese Patent publication No. 7-51242. However, in a type of device in which the electrode elements are secured at a predetermined position, the device is not capable of adjusting for differences in examinee's body heights so that the difference in angle between torso regions and arm regions may be extremely increased to result in making a measured value incorrect upon some examinees' measurement. Further, even if an examinee attempts to maintain an appropriate right angle position by the examinee's visual adjustment, the angle is, in fact, changed in each measurement resulting in an unstable measured value.
It is accordingly an object of the present invention to solve the above problem and to provide a device capable to obtain accurate and stable in-vivo impedance with hand electrodes, and also to provide a device for effectively utilizing in-vivo impedance measured accurately with the hand electrodes.